I'm dual booting from SSD (Win8) and IDE (Win7) without having to go into the bios. I just had to OS install both of them with the other drive disabled.
Then I just press the boot function key (For ASUS F8) and choose which drive to boot from.
I've also installed Win8 first and then Win7 secondly on the same setup but with both drives functional. Then a bootloader is setup in the main boot drive (win8) and when I start up the machine I get to choose after the initial system boot. The problem with that method is that if the first drive fails, so does the boot loader and now I have to perform a short win8 repair for it to recognize that there's only one OS left and setup for that.
Nono, SSDs are too rich for my blood. I'm running two SATA HDD's. Both of them are SATA 3's. A 1.5 TB with 8 and a 500GB with 7. I get to the selection screen, I select Windows 7, it kicks me back to the selection screen. So I go into BIOS without making any changes, exit and it boots 7 no problem. If I set 7 as default in msconfig, it takes me to the win7 bootloader and it does the same thing. I have never seen anything like this..
Also, it could be that my secondary HD needs to be set as the slave.. I've tried everything else.